This is a famous type of CAPTCHA, which requires humans to type two words which have been crossed out or obscured in some way

These tests are security mechanisms designed to prove someone is human by asking them to identify words or pictures.

But researchers from a tech firm called Vicarious have built a computer program based on the human brain’s visual system which has solved a CAPTCHA puzzle.

The development is significant because it was previously believed that computers would only be able to crack the tests when they have achieved full artificial intelligence and become as intelligent as humans.

“Our work… is a small step in endowing computers to understand letterforms with the flexibility and fluidity of human perception,” the company wrote.

The firm developed software called the Recursive Cortical Network to crack the tests with 90 per cent accuracy.

Normally, computers find CAPTCHA tests impossible to solve.

The puzzles generally use letters or words which are deliberately made impossible for computers to recognise, but easy for humans who are able to identify a letter or number that’s been written in a strange way or crossed out.